This invention relates to studs and bolts and more particularly to a novel fastener for use in wood, rubber and other non-metallic materials, which requires no preformed bore therefor.
Wood, rubber and other soft or plastic parts are commonly fastened together or to other materials by means of fasteners which require preformed bores either threaded or plain or a combination of such preformed bores and embedded or molded in metal parts to which the fasteners are attached. Examples of such arrangements are the methods used to fasten rubber of other resilient materials as liners to drums, tanks, vats, storage vessels, trucks, chutes or mills, fastening of plastic to metal parts, means used to hold wood and/or wood or metal together in the construction of homes, cabinets, furniture, ships, plywood, concrete forming systems, commercial structures, mobile homes and vehicles.
Some of the methods and inventions used are described in U.S. Pat. Nos: 3,378,209, 3,599,827, 2,687,230, 2,328,728 and 2,058,257.
Screws are used without preboring holes in relatively light load situations but have the disadvantage of being relatively easy to pull out and distorting or destroying the base material because of displaced material buildup, if they are inserted into narrow sections. Split screws or screws with hollow centers have been described to solve these problems but have failed to gain commercial acceptance because of the high cost to produce them or their inability to solve the problems within the parameter of modern production methods. Such articles are described in U.S. Pat. Nos: 1,729,670, 1,368,896 and 126,366.